Lab 8: The Twelve Days of Christmas

Sing the Full Song

Author

Your name

library(tidyverse)
xmas <- read.csv("https://raw.githubusercontent.com/zoerehnberg/STAT331-S23/main/practice_activities/xmas.csv")

Download starter .qmd file

You’ve already created two helper functions, pluralize_gift() and make_phrase(), which you used to create a column of song phrases in the practice activity.

Today, you will write a function that sings the appropriate lines of the song for a given day. We will then use this function to iterate through the 12 days of Christmas to sing the full song!

1 Helper Functions

Note

You will need to copy over your functions from the practice activity into your new lab Quarto document.

# Copy over functions from your practice activity!

Use your PA functions to create a Full.Phrase column in the xmas2 dataset.

xmas2 <- xmas |>
  mutate(
    Full.Phrase = pmap_chr(.l = list(num       = Day,
                                     item      = Gift.Item, 
                                     verb      = Verb, 
                                     adjective = Adjective, 
                                     location  = Location), 
                           .f = make_phrase))

Error in `mutate()`:
ℹ In argument: `Full.Phrase = pmap_chr(...)`.
Caused by error:
! object 'make_phrase' not found

2 Iteration

Write a function called sing_day() that takes as input:

A dataset (input as a dataframe).
A number indicating which day to sing about (input as an integer).
The name of a column in the dataset that contains the phrases for each day (input as a tidy name).

For example,

sing_day(xmas2, 2, Full.Phrase)

should return

On the second day of Christmas, my true love sent to me:
two turtle doves and
a partridge in a pear tree.

Tip

Hint 1: The {phrase_col} part, which I provided for you, lets you use column names as arguments to a function. Don’t delete that line of code!

Hint 2: The ordinal() function from the english package could be helpful when converting the line input (e.g., 1) to a word (e.g., “first”).

# Produces the string for one day of the song.
# Arguments:  dataset -- a dataframe containing information about gifts.
#             num -- the number of the day you want to sing about.
#             phrase_col -- the variable name for the column in dataset with the song phrases.
# Returns:    a string with the line of the song containing ALL gifts for the given day.

sing_day <- function(dataset, num, phrase_col){
  
  # Step 1: Setup the intro line
  # Hint: You need to convert a number (e.g., 1) to a word (e.g., first)
  num_word <- ____
  
  intro <- glue::glue("On the {num_word} day of Christmas, my true love sent to me:")
  
  # Step 2: Sing the gift phrases
  # Hint: What order are they gifts sung in each day?

    phrases <- dataset |>
      pull({{phrase_col}})

  ????
    
  ## put it together
    
  ????

}

Error in parse(text = input): <text>:11:16: unexpected input
10:   # Hint: You need to convert a number (e.g., 1) to a word (e.g., first)
11:   num_word <- __
                   ^

A Small Test

xmas2 |>
  sing_day(num = 2, phrase_col = Full.Phrase)

Error in sing_day(xmas2, num = 2, phrase_col = Full.Phrase): could not find function "sing_day"

3 Sing the Song

Run the following code to test out your functions! The output should be the lyrics for the entire The Twelve Days of Christmas song.

map_chr(1:12, ~ sing_day(dataset = xmas2, 
                         num = .x, 
                         phrase_col = Full.Phrase)) |>
  str_c(collapse = "\n") |>
  cat()

Error in `map_chr()`:
ℹ In index: 1.
Caused by error in `sing_day()`:
! could not find function "sing_day"

Warning

You will get automatic deductions for:

Functions that do not work the way they are intended.
Hard coding values in your in functions.
Not using the map() code supplied for you to iterate the function you just wrote.
Not singing the full song. Remember, each day, you get the gift for that day and all the prior days.

4 Style the Song Output

Let’s output the song in a visually appealing way!

Note

Make the following changes to your sing_day() function above. Do not copy the code to a new code chunk for the style section.

a. Remove any additional whitespace.

There should be only one whitespace character between words.
There should be no whitespace at the beginning or end of each phrase.

b. Print each phase on its own line.

For example, your function should output the following for sing_day(xmas, num = 2, phrase_col = Full.Phrase):

On the second day of Christmas, my true love sent to me: 
two turtle doves and 
a partridge in a pear tree

c. Add blank lines between the different lines of the song.

For example, your output should look like the following:

On the first day of Christmas, my true love sent to me:
a partridge in a pear tree

On the second day of Christmas, my true love sent to me: 
two turtle doves and 
a partridge in a pear tree

d. Ensure the lines of your song are grammatically correct.

Use of Commas – each line should end in a comma except for the last line.
Use of And – there should be an “and” included either at the end of the second to last line or at the beginning of the final line.
Use of Period – there should be a period at the end of the final line.

For example, your function should output the following for sing_day(xmas, num = 3, phrase_col = Full.Phrase):

On the third day of Christmas, my true love sent to me: 
three french hens, 
two turtle doves and 
a partridge in a pear tree.

Note

While I am a fan of the Oxford comma, you do not have to use an Oxford comma for the second to last phrase of your song.

--- title: "Lab 8: The Twelve Days of Christmas" subtitle: "Sing the Full Song" author: "Your name" format: html: embed-resources: true code-tools: true toc: true number-sections: true editor: source execute: error: true echo: true message: false warning: false --- ```{r setup} library(tidyverse) xmas <- read.csv("https://raw.githubusercontent.com/zoerehnberg/STAT331-S23/main/practice_activities/xmas.csv") ``` [Download starter .qmd file](LA8_fprogram.qmd) You've already created two helper functions, `pluralize_gift()` and `make_phrase()`, which you used to create a column of song phrases in the practice activity. Today, you will write a function that sings the appropriate lines of the song for a given day. We will then use this function to iterate through the 12 days of Christmas to sing the full song! ## Helper Functions ::: callout-note You will need to copy over your functions from the practice activity into your new lab Quarto document. ::: ```{r} # Copy over functions from your practice activity! ``` Use your PA functions to create a `Full.Phrase` column in the `xmas2` dataset. ```{r} xmas2 <- xmas |> mutate( Full.Phrase = pmap_chr(.l = list(num = Day, item = Gift.Item, verb = Verb, adjective = Adjective, location = Location), .f = make_phrase)) ``` ## Iteration Write a function called `sing_day()` that takes as input: + A dataset (input as a dataframe). + A number indicating which day to sing about (input as an integer). + The name of a column in the dataset that contains the phrases for each day (input as a tidy name). For example, sing_day(xmas2, 2, Full.Phrase) should return On the second day of Christmas, my true love sent to me: two turtle doves and a partridge in a pear tree. ::: callout-tip **Hint 1:** The `{phrase_col}` part, which I provided for you, lets you use column names as arguments to a function. Don't delete that line of code! **Hint 2:** The `ordinal()` function from the **english** package could be helpful when converting the `line` input (e.g., 1) to a word (e.g., "first"). ::: ```{r sing-day-function} # Produces the string for one day of the song. # Arguments: dataset -- a dataframe containing information about gifts. # num -- the number of the day you want to sing about. # phrase_col -- the variable name for the column in dataset with the song phrases. # Returns: a string with the line of the song containing ALL gifts for the given day. sing_day <- function(dataset, num, phrase_col){ # Step 1: Setup the intro line # Hint: You need to convert a number (e.g., 1) to a word (e.g., first) num_word <- ____ intro <- glue::glue("On the {num_word} day of Christmas, my true love sent to me:") # Step 2: Sing the gift phrases # Hint: What order are they gifts sung in each day? phrases <- dataset |> pull({{phrase_col}}) ???? ## put it together ???? } ``` ::: callout-note ### A Small Test ```{r} xmas2 |> sing_day(num = 2, phrase_col = Full.Phrase) ``` ::: ## Sing the Song Run the following code to test out your functions! The output should be the lyrics for the entire *The Twelve Days of Christmas* song. ```{r} map_chr(1:12, ~ sing_day(dataset = xmas2, num = .x, phrase_col = Full.Phrase)) |> str_c(collapse = "\n") |> cat() ``` ::: callout-warning **You will get automatic deductions for:** + Functions that do not work the way they are intended. + Hard coding values in your in functions. + Not using the `map()` code supplied for you to iterate the function you just wrote. + Not singing the full song. Remember, each day, you get the gift for that day *and* all the prior days. ::: ## Style the Song Output Let's output the song in a visually appealing way! ::: callout-note Make the following changes to your `sing_day()` function above. Do not copy the code to a new code chunk for the style section. ::: **a. Remove any additional whitespace.** + There should be only *one* whitespace character between words. + There should be *no* whitespace at the beginning or end of each phrase. **b. Print each phase on its own line.** + For example, your function should output the following for `sing_day(xmas, num = 2, phrase_col = Full.Phrase)`: ``` On the second day of Christmas, my true love sent to me: two turtle doves and a partridge in a pear tree ``` **c. Add blank lines between the different lines of the song.** + For example, your output should look like the following: ``` On the first day of Christmas, my true love sent to me: a partridge in a pear tree On the second day of Christmas, my true love sent to me: two turtle doves and a partridge in a pear tree ``` **d. Ensure the lines of your song are grammatically correct.** 1. *Use of Commas* -- each line should end in a comma *except* for the last line. 2. *Use of And* -- there should be an "and" included *either* at the [end]{.underline} of the second to last line *or* at the [beginning]{.underline} of the final line. 3. *Use of Period* -- there should be a period at the end of the final line. + For example, your function should output the following for `sing_day(xmas, num = 3, phrase_col = Full.Phrase)`: ``` On the third day of Christmas, my true love sent to me: three french hens, two turtle doves and a partridge in a pear tree. ``` ::: callout-note While I am a fan of the Oxford comma, you do not have to use an Oxford comma for the second to last phrase of your song. :::